The present invention relates generally to optical resonators, and more particularly, to optical ring resonators which employ the principles of phase conjugation.
A great deal of research and development is currently in progress which relates to the application of phase conjugation principles to the correction of laser beam profiles. In particular, the phase conjugation process known as stimulated Brillouin scattering has received wide attention, both in terms of determining a theoretical understanding of the process and in experimentation related thereto.
Numerous publications exist which discuss various features of stimulated Brillouin scattering as they apply to various laser sources and associated nonlinear media in which the scattering process may occur. These publications include "Multiple Stimulated Brillouin Scattering From a Liquid Within a Laser Cavity", by A. J. Alcock et al, Applied Physics Letters, Vol. 11, No. 2, 15 July 1967; "Cancellation of Phase Distortion in an Amplifying Medium With a Brillouin Mirror", Nosach et al, ZhETF Pis. Red. Vol. 16, No. 11, 5 Dec. 1972; "Connection Between the Wavefronts of the Reflected and Exciting Light in Stimulated Mandel'Shtam-Brillouin Scattering", Zel'dovich et al, ZhETF Pis. Red. Vol. 15, No. 3, 5 February 1972; "Correction of Phase Aberrations Via Stimulated Brillouin Scattering", Wang et al, Optics Letters, Vol. 2, page 4, January 1978; and "Stimulated Brillouin Scattering in Optical Fibers", E. P. Ippen et al, Applied Physics Letters, Vol. 21, No. 11, 1972.
However, although there has been much research and development in the phase conjugation area, the concepts of phase conjugation have not been applied to ring resonator devices. Ring resonators are well-known in the laser art, and exemplary ring resonators are shown and discussed in U.S. Pat. No. 3,691,477, and publications by C. L. Tang et al, Journal of Applied Physics, Vol. 34, p. 2289 (1963) and A. H. Rosenthal, JOSA, Vol. 52, p. 1143 (1963).
Therefore, it would be an improvement in the laser art to provide a ring resonator device which employs the concepts of stimulated Brillouin scattering, and which is capable of providing a phase-compensated difraction-limited output beam.